Glow discharge tubing and means for mounting the same



y 1944- v H. EPSTEIN I 2,349,255 I GLOW DISCHARGE TUBING AND MEANS FOR MOUNTING, THE SAME I 7 Filed Nov. 10, 1941 V Patented May 23, 1944 PATENT *OFFICEVI otowmscnanou TUBING AND MEANS sou MOUNTING THE SAME Iiirsch Epstein, Chicago, Ill.

Application November 10,

1941, Serial No. 418,469

3 Claims. (01. 176122) This invention relates to glow discharge tubing and to terminals and mountings therefor, and more particularly for fluorescent type tubing.

Fluorescent tubing generally consists of a transparent glass-like tube coated with the usual fluorescent chemicals and provided at each end with a terminal structure for extending the electric circuit to the tubing. The terminal structure, in one standard form of hot cathode type tube, consists of a short metal cap sealed to the end of i the glass tubing ,and which cap has a pair of metal studs or plugs extending outwardly therefrom for receiving the electrical connections.

. The metal studs extend the circuit to a hot cathode within the tube. The metal studs are adapted to be received in asocket which may be of a. well known construction. In the case of straight fluorescent tubes a socket at each end holds the tube against longitudinal movement and thus supports it in the socket. In the case of a curved 2i) tube, especially one, ior instance, oi a iii-shape. the two ends of the tube are adjacent one another and therefore it the tube is to be held in other than in a position extending vertically upward from the sockets it is necessary that some ineans be provided for holding the, tube against inadvertent'retraction from the sockets.

It is one or the objects of the present invention to provide means which can he used in connection with standard types 01 fluorescent tube terminals for releasably locking the tube terminal to the socket and thus hold the tube in place. It is a further object of the present invention to provide such an arrangement wherein the amount or change that must be wrought in the standard tube or socket is reduced to a minimum. In accordance with one embodiment of the present invention this is accomplished by providing a slight change in the tube terminal and no change whatsoever, in th socket. In accordance 40 with the preferred embodiment of the present invention narrow slots are formed in the metal cap at. the end oi the fluorescent tube, which slots are adapted to receive the ends oi a spring clip that is positioned to embrace the associated socket and thus hold the fluorescent tube against Straight fluorescent tubes can be made in standard lengths so that there is practically no deviation between the lengths or diiierent'tubes. 5c

' When this is thecase the sockets for receiving the ends of a tube of a ghren standard length may be mounted in place the necessary fixed distance apart without any great Monitor. In

the manufacture of curved fluorescent tubes the locations of the terminals or capsof a tube, with respect to one another, cannot be gauged with as high a degree of precision as in the case of straight tubes. It is therefore necessary to. mount atleast one of the sockets for receiving .the tube in such a manner that adjustments can be made in the relative positions of the two sockets to receive difierent tubes of the same so called standard size but which difler irom one another an amount sumcient to require adjustments of the relative positions of the sockets. In accordance with the principles of the present inven tion one or both of the two sockets for receiving the two ends of a fluorescent tube is so mounted as to be adjustable. As a result the positions of the sockets can be adiusted with respect tonne another to compensate for small difierences in the relative locations of the two end caps of different curved tubes wherein the deviations are such as are normally encountered in the usual factory production methods;

It is a still further object of the present invention to provide means for loclring and holding the end cap of a fluorescent tube with respect to the terminal socket so as to maintain contact between the prongs oi the tube and the sachet even though they are at a slight angle to one another. I

The attainment of the above and further ob- Jects of the present invention will be apparent from the following-specification taken in corn junction with the accompanying drawing 'iorm- Q line 4-4 or 02 Figure 1 and looking in the direction of the arrows;

Figure 5'15 a section taken along the line M 0! Flame 4 and looking in the direction of the arrows: Figure 61': aviewaimilartof'isuretandehow ing an alternative type of mounting for the socket; V

Figure l is a perspective view or the spring clip used in-the structure of Figure I;

Figure 8 is a perspective view showing the manner of mountina and supporting the tube of Figure 1 in a horizontal position; and

Figure 9 shows how the present invention is applicable to tubing curved through an angle of approximately 90.

Reference may now be had more particularly to the structure illustrated in'Figure 1. In this figure I indicates a glow discharge fluorescent light which includes a glass tube circular in cross section and bent into a substantially U-shape. The tube is coated on the inside with the usual fluorescent materials, is provided with the usual hot cathodes at each end and the usual heating filaments 2 at each end as is known in the art. The tube is sealed, evacuated and filled with the proper gas or gases at the usual sub-atmospheric pressure, as is well known in the art. A metal cap 3 is cemented to each end of the tube, one said cap consisting of a small ring that flts over and is cemented to the end of the tube I and has a shallow periphera1 groove 4 adjacent the 1 end thereof. The cap also includes a disc 6 of insulating material held in place by the grooves 4 and an-outer rim 1 of the cap. Apairof terminal prongs 8-8 extend through and are held by the disc 8. The terminal prongs are connected within the cap to wires that are sealed through the glass body of the tube and connect to the opposite ends of a heater or filament 2 for a hot cathode, which filament may constitute the cathode. all as is well known in the art. The fluorescent light of the present invention differs from standard type of commercial hot cathode fluorescent lights essentially only in that the glass tube is bent to a U-shape instead of being straight and, further, that the cap 3 differs from a standard cap in that a pair of narrow slots 9-3 are milled in the cap at opposit sides thereof in the groove 4.

Each cap 3 is adapted to be received in a standard type of socket, indicated at III. The socket ID has two slots I I-II therein in which the terminal prongs 8-8 of the metal cap slide, said slots being bent at substantially right angles, as indicated at I2-I2, in a manner well known in the art. The prongs 8 are releasably held in place by spring clips I3I3 in the socket, as is well known. The socket is of a standard well known construction and no novelty is claimed therein per se. In Figure 1 the sockets IIII0 have been mounted to receive a fluorescent tube a radius of approximately that of the cap 3, if desired. While the end of the tube is .manually held in the'socket I8 the clip is slipped over the back of the socket, the arms I8-I8 are sprung apart slightly and then released to permit the flanges I8-I8 to enter the slots 98in the cap 3. The clip thus rests on the back of the socket and supports the tube against downward movement. The prong's l-O of the tube within the recesses I2 are thus also held against sliding out of the socket by way of the slots II. It is thus apparent that each terminal end of the tube I is flrmly held in its socket II.

In those cases where the tubes I are of standard sizes so constructed that there is no deviation The free ends of .the flanges I8-I8 may be slightly curved, along in the distances between the metal caps 3-4 of Y the tube the sockets may be mounted rigidly on tion in distances between the metal caps 33 of a non-straight tube are such that if the sockets I0III are rigidly supported at fixed distances apart the terminal prongs of the two ends of the tube will not be accurately opposite the terminal receiving slots II-II of the two sockets Ill-I0. In such instance it is necessary to change the position of at least one of the sockets each time a tube I is replaced by another tube. This difliculty is eliminated in accordance with the principles of the present invention by mounting one or both of the sockets in such a manner as to permit adjustment of the position of the socket.

A description will now be given of the manner of mounting the socket III. -The socket III it self is a standard socket consisting of a, base 25 from which extends an upright 26, of rectangular cross section, the base and upright consisting of a single piece of insulation such as porcelain, Bakelite, or any other suitable insulation. The base 25 has a slot 21 extending therethrough at the forward edge thereof, and has two notches 28-48 formed therein for receiving the circuit extending conductors. the base through the upright 26 to terminals opposite the slots I 2I2. In the present instance the base 25 of the socket I0 is mounted on the rear side of a supporting plate 30.- The upright 26 extends through a hole 3| in the plate 30, the hole being slightly longer and slightly wider than the width and thickness of the upright 26 so that the upright has complete freedom of play both as to shifting and tilting while it extends through the hole 3|. A thick soft rubber plug or cushion 33 is interposed between the top surface of the base 25 and the plate 3I. A screw 34 extends loosely through a slightly oversized hole in the plate 30, through the plug or cushion 33, through a ,washer 35 which bears against the base 25, and through the slot 21 and has a nut 38 threaded thereon and bearing against the bottom of the base. Thescrew 34 is tightened an amount sufficient to place the plug or cushion 33 under considerable pressure but still allow for a considerable possible increase of pressure.

The socket I0 is thus held in position on the wall 38 and yet is adjustable angularly up and down and-from left to right in the oversized'hole 3| while the screw 34 continues to hold the socket in place. Thus if one of the metal caps 3 is out of relative position with respect to the other cap on the fluorescent tube the adjustable socket II! can be shifted towards or away from the other socket or can be shifted up or down angularly to bring it into proper position for receiving the terminal prongs 8-8 of the adjacent cap 3. In the preferred arrangement both sockets I 0Il are adjustably mounted so that any deviation in proper alignment of the two metal caps is taken up by relativemovement of both sockets whereby each socket need adjust for only half of the deviation. The spring clip I8 maintains the caps ion 33 as located between the supporting platefl 8i and the base 23 of the socket, it is within the purview of the present invention to mount the yielding means on the opposite side of the base so that the yielding means is between thebase 25 and the nut 38. This is illustrated in Figure 6. In this flgure a small metal ring 48 having 'a rounded nose H is interposed between the The circuit extends from "the spring clips it.

asiaass base 28 and the plate 30. The screw 34', which corresponds to the screw-34 of Figure 4, extends through thering and through the slot 21 in the socket 25, as before. The yielding means, in this instance is in the form of a coiled spring 43, and is interposed between the base 25 and the nut 38 that is threaded on the screw 34', a washer being positioned between the nut 38 and the spring 43. The screw is tightened to place the spring 43 under pressure. It is thus apparent that the socket IU of Figure 6 is universally adjustable in any direction by swiveling with'the screw 34' in the same manner as is the corresponding structure of Figure 4.

While I have shown the U-shaped fluorescent tube 1 of Figure 1 mounted in a position depending from the sockets. it is clear from the description thus far given that the tube will remain in the sockets even if it is mounted in any position other than that illustrated in Figure 1. For instance, in Figure 8 I have illustrated the tube l as extending horizontally from the sockets lO-Hl. At this time the weight of the tube tends to swing the tube downwardly with respect to the sockets. This is resisted by the spring clips it which embrace the sockets and which extend into the slots 9 of the cap 3. The tube cannot fall downwardly through the slots HH in the socket in because the prongs I of the tube rest in the parts l2-l2 of the slots H. from the sockets it is first In Figure 9 I have shown the principles of the present invention as applied to a tube of a curvature less than 180', in this instance a tube curved through an arc of approximately 90. The individual sockets ll'|l are mounted in a. wall in the manner indicated in Figure 4 or in Figure 6,

it embraces each socket and locks the corresponding end of the tube to the socket so that no gravitational forces can cause removal of the tube from the two sockets. If the tube is slightly too long or too short for the normal distance between the sockets, the two sockets may be tilted towards or away from each other and then locked to the corresponding ends of the tube by the clips 16-.

In compliance with the requirements of the patent statutes I have here shown and described a preferred embodiment of my invention. It is, however, to be understood that the invention is not limited to the precise construction here shown, the same being merely illustrative of the principles of the invention.

What I consider new and desire to secure by Letters Patent is:

1. A glow discharge device comprislngaesealed tube,--a cap secured on the end of the tube, a plurality of prongs projecting from the cap for extending circuit connections to the tube, and means for facilitating securing the tube against removal from a socket. said means comprising a pair of clip-receiving perforations in the cap and 180 apart.

4 In combination with a glow discharge device using a plug-in type terminal at an end thereof. a socket into the front of which the terminal amends to establish circuit connections with the terminal, and a releasable clip extending completely across the back and sides of the socket and with the end of the clip engaging the end of In order to remove the tube necessary to remove the glow discharge device for holdingthe device and the socket together against separating movement in a direction lengthwise of the'device.

3. In combination, a glow discharge device comprising'a tube bent so that the longitudinal axes of the ends thereof are spaced apart, a ter-- minal cap secured to the tube at each end thereextending circuit connections to the device, each socket including a mass of solid insulation and contact making means therein, a supporting structure on which the sockets are mounted, means securing the sockets to the structure and permitting relative movement oi. the sockets with respect to one another to equalize the distance between the sockets to the distance between the terminal caps, each of said caps having at least one clip-receiving slot therein, and a clip securing the cap to its associated socket, said clip extending into said slot.

4. In combination, a pair of cooperating sockets, adapted to receive and support the ends of a glow discharge tube between them, each socket including a mass of solid insulation and contact making means therein, a resilient support for at least one of the sockets to allow a limited movement of that socket towards the other socket, a glow discharge device comprising a tube having a terminal cap secured to each end thereof, said cap having terminal projections extending therefrom and insertable into said sockets, said tube being bent so that the center of gravity of the device is substantially spaced from a straight line Joining the centers of the terminal caps, and a clip embracing at least one of the sockets with the ends of the clip hooked to the terminal cap associated with said socket to hold the socket and the tube against separating.

5. In combination, a pair of spaced cooperating sockets adaptedto receive and support the ends of a glow discharge device between them, each socket including a mass of solid insulation and contact making means therein, and a rocking support for the mass of insulation of at least one of the sockets permitting a rocklng'movement of the complete socket with respect to the other socket to bring it closer to or further from the other socket to compensate for variations in the distance between the ends of different glow discharge devices.

6. In combination, a pair of cooperating sockets adapted to receive and support plug type ends of a glow discharge device between them, each socket including a mass of solid insulation and contact making means therein, a rocking support for at least one of the sockets permitting a rocking movement thereof to bring it closed to or further from the other socket to compensate for variations in the distance between the ends of different glow discharge devices, and means for locking the two sockets and the ends of a glow discharge device against separation in a direction axially of the plug ends of a device whereby the sockets support the device and the device maintains the sockets the requisite distance apart determined by the distance between the ends of the device.

7. In combination, a glow discharge device comprising a sealed U-shaped tube having plugin type terminals at the opposite ends thereof, spaced sockets for receiving the terminals of the tube, and means for locking the terminals of the tube in the sockets and holdingthe tube against lengthwise movement out of the sockets, said means comprising a pair oi clips each extending completely across the back and sides of a socket vice. v

8. In combination with a glow discharge device having at the end thereof 0. prong plug-in type terminal, means for supporting the device and establishing electric connections thereto, said means comprising a socket into which the prong terminal is movable and from which it is retractable by a movement longitudinally of the prong, and means for releasably locking said device against such longitudinal movement, said last means comprising a clip carried by the socket and hooked to the glow discharge device and including a part extending from the socket to the device in a direction lengthwise of the prong and held by the socket against movement in a direc-' tion having any substantial component lengthwise of the prong and with the end of the said lengthwise extending part of the clip terminating in a clip part that extends radially towards the central'axis of the device and engages the device to hold the prong against movement lengthwise of the prong.

- HIRSCH EPSTEIN.

CERTIFICATE OF CORRECTION.

Patmi No. 2,5h9,255.' M y 5, 9M.-

HIRSGH EP STEIN.

It is hereby certifi ed that error appears in the printed specification of the above numbered patnt requiring correci ilon as follows: Page 5, sec-- and. column, line 57 claim 6, for- "cloaad" r'aad closer'---; and mt the said Letters Patent should be read with this correction therein that the same may confom to tho'record of the cane In the Pdtent Office.

Signed and sealed this 25th day of Jul A. D. 191 1;.

Leslie irazer (86411) Actln g Commissibner of Patents. 

